This invention relates to cold forging apparatus for forming complex articles and more particularly to cold forging apparatus for performing multiple functions at a single station. It also relates to a conveyor or loader/unloader for such apparatus.
Cold forging apparatus and processes are well-known. Such apparatus and processes have been used for many years in the commercial production of relatively simple parts at a single station or more complex parts with a multi station set up. However, for more complex parts, the use of a multi station process requires duplication of equipment, additional set-up time, additional space, multiple dies and additional costs. Such costs are particularly excessive for making a limited numbers of forged parts.
More complex parts may also be forged in a machine such as an automatic forging press or cam operated cold header. In such machines, parts are transferred through a variety of stationary die sets, each of which includes a punch. Such machines are capable of operating at high speeds, but are complex, expensive and require considerable set-up time before each run. Accordingly, the use of such machines is generally limited to high volume items where the length of the run justifies the set-up time. The use of such machines is also generally limited to parts which have sufficient complexity and sufficient market value to justify the costs of the machine, set-up time and other operating costs.
In our earlier application Ser. No. 10/291,361 which was filed on Nov. 12, 2002, we disclosed a cold forming apparatus for forming complex shapes at a single station. As disclosed therein, the apparatus includes a multi-function punch assembly including an inner and outer punch disposed on a common axis and a third punch in a confronting relationship with the first punch assembly. The apparatus also includes a die and a die holder for positioning a mass of metal or slug between the punches. A computer system controls movement of the punches and is programmable to form parts of different shapes at a single station.
It is now believed that there is a commercial market and need for an improved cold forging apparatus in accordance with the present invention. The reason for such demand is that such apparatus offer numerous advantages, for example, such apparatus are capable of forming complex shapes at a single station. Further, the apparatus requires less space and in some cases fewer operators than multiple machines each of which performs a single step in the production of a complex part. The apparatus as disclosed herein also require less set-up time which enables an operator to produce shorter runs at economical costs. This is because fewer stations and less tooling results in lower production costs, particularly in those cases involving smaller volumes of parts. A further advantages resides in a conveyor or loader/unloader for automatically or semi-automatically transferring a metal work piece or metal slug from a supply area to a loading/unloading area between the punches in a cold forging apparatus. The loader/unloader is also adapted to pick up a forged product from a loading/unloading area and unloading the forged product into a storage area or tray. Also, the loader/unloader in accordance with the present invention is adaptable for loading and unloading different apparatus.
A further advantage of the apparatus of the present invention resides in the use of multiple machines which includes conveyors in accordance with the present invention. Such machines may be slower than the aforementioned cam operated cold headers, but provide greater flexibility and backup in the event of a machine failure or down time for a more complex machine. In addition, cold forging apparatus in accordance with the present invention can be produced and sold at a competitive price. For example, it is presently estimated that the cost of a cold forging apparatus in accordance with the present invention is less than 25% of the cost of an automatic cam operated forging press. A still further advantage resides in the use of a computer program in conjunction with multiple sets of punches at a single station. It is also believed that the apparatus in accordance with the present invention will be less complex, less expensive to install, operate and maintain and more reliable than the automatic cam operated cold headers of the prior art. Recognizing, that the prior art automatic cam operated cold headers are capable of relatively fast speeds, it is believed that the use of two, three or more machines in accordance with the present invention will be capable of matching those speeds while providing many of the aforementioned advantages including costs and added flexibility.